Recently, depletion of existing energy sources such as oil and coal has been predicted, and interest in energy that can replace the energy is increasing. A fuel cell as one of the alternative energy has particularly received attention due to high efficiency and merits such that pollutants such as NOx and SOx are not discharged and the used fuel is abundant.
The fuel cell is a power generation system that converts chemical reaction energy of the fuel and an oxidizer into electric energy, and hydrogen and hydrocarbons such as methanol and butane as the fuel and oxygen as the oxidizer are representatively used.
The fuel cell includes a polymer electrolyte membrane fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell (PAFC), an alkaline fuel cell (AFC), a molten carbonate fuel cell (MCFC), a solid oxide fuel cell (SOFC), and the like.
Meanwhile, research on a metal air secondary battery that manufactures a cathode of the metal secondary battery as an air electrode by applying a principle of the air electrode of the fuel cell is required.